The benefits of metformin in diabetes are well established, and it’s no surprise that it is the first choice of medication for treatment of type 2 diabetes. Metformin can lower the hemoglobin A1c by 1-2% and improve insulin sensitivity. It is well tolerated for most patients, although some have severe gastrointestinal issues and are unable to take it. Some patients may also develop neuropathy after long term use, likely related to vitamin B-12 deficiency due to decreased absorption in the GI tract.
Metformin is also effective for other conditions such as polycystic ovarian syndrome, prediabetes, and weight loss.
Studies have also shown a potential role for metformin in reducing cancer risk. By improving insulin sensitivity, the amount of insulin circulating in the bloodstream is decreased. This leads to a decrease in the proliferation of cancer cells that express insulin growth factor (IGF) receptors.
One study showed a decrease in the risk of liver cancer among users of metformin. Patients on metformin with aspirin or metformin with a statin had an even lower risk of liver cancer.
Another study showed a decreased risk of gastric cancer in patients on metformin, after eradication of H. pylori infection, a significant risk factor for gastric cancer.
We know that patients with type 2 diabetes are more likely to develop cancer, but the mechanism behind that is not fully clear. In a comparison with other blood sugar lowering medications, metformin was shown to be more effective at reducing the risk of developing solid tumors. This suggests that lowering blood sugar is not the only mechanism at work.
Perhaps the best news is that most forms of metformin are very inexpensive. Some stores even give it away for free .